The present invention relates to development of a suitable column to adsorb leukemic cells selectively from the blood of leukemic patients for the purpose of therapeutic treatment, and a leukemic cell-adsorbent material used therein.
The current therapeutic treatment of leukemia is to undertake transplantation of a healthy marrow following the administration of anticancer agents and radiation. Anticancer agents are administered until leukemic cells disappear in blood, which in general exhibits strong side effects to the patient of leukemia. They must endure a very severe life under the medical care for a quite long time. In addition, it is sometimes not certain that the relapse into the disease can be fully prevented even by a prolonged administration of anticancer agents.
On the other hand, a novel promising therapeutic way for leukemia has become highlighted by the discovery of lectin proteins derived from certain plants and animals which act as leukemic cell-capturing agents capable of recognizing leukemic cells specifically as reported in Japanese Patent Kokai 9-206096. This leukemic cell-capturing agent can discriminate leukemic cells.from normal cells in the blood by recognizing the sugar chains expressed on the cancer cells specifically so that the lectin protein is expected to remove leukemic cells from body fluids very efficiently.
It is a usual way to treat cancer patients by anticancer agents which are administrated either orally or parenterally to make the anticancer agents contact with the cancer cells through the circulatory blood system of the patient""s body.
A problem in this way is that the anticancer agents reach not only the target tissues but also other tissues in the whole body of the patient, because the anticancer agents are administered in a dose much larger than the actual desired dose for the target tissues after being diluted in blood stream over the whole body. Therefore, it is sometimes unavoidable that the body tissues other than the target tissues are subjected to unpredictably adverse side effects of the anticancer agents.
So far, attempts have been made repeatedly in order to develop a therapeutic treatment method by which the anticancer agents are concentrated to the target tissues as limitedly as possible to attack the cancer cells effectively. Unfortunately, however, no fully promising results have yet been obtained.
The primary object of the present invention is accordingly to provide a speedy and efficient means for the therapy of leukemia by bringing the leukemic cells in the externally circulating patient""s body fluid into direct contact with a leukemic cell-capturing agent so as to remove the leukemic cells from the body fluid of the patient.
The secondary object of the invention is to provide a novel leukemic cell-adsorbent material capable of capturing the leukemic cells selectively to remove the leukemic cells from the patient""s body fluid, and to accomplish a rapid and reliable therapeutic result on the disease as well as an apparatus for leukemic cell adsorption.
Thus, the leukemic cell-adsorbent material provided by the present invention is a composite material which comprises:
(a) a leukemic cell-capturing agent which is a lectin protein derived from the body of a specific mushroom fungus such as Agrocybe cylindracea or a seed of a leguminous plant such as jequirity; and
(b) a physiologically inert carrier material supporting the leukemic cell-capturing agent as the component (a) by forming a chemical bonding therebetween.
The leukemic cell-adsorbing column provided by this invention is a tubular body made of an insoluble and physiologically inert material holding a bed of the leukemic cell-adsorbent material defined above therein.